Cotton, a freshman congressman, called on his former drill sergeant, George Norton, to take part in the 30-second commercial to poke fun at his opponent.

Dressed casually in an open shirt, Cotton says in the ad, "Sen. Pryor says my military service gives me, quote, a sense of entitlement. So I brought in an expert."

The tough drill sergeant then jokingly says "at ease" to Cotton, who served in the Iraq War and Afghanistan.

Cotton was referring to comments Pryor made last month on MSNBC’s "Morning Joe" when he declared that Cotton’s military service did not necessarily qualify him for the Senate.

"I think that is part of this sense of entitlement that he gives off," Pryor said. "It’s almost like, ‘I served my country, let me into the Senate.’ That’s not how it works in Arkansas."

Pryor added that he has "great respect" for people in the military and thanked Cotton for his service.

In the ad, Cotton continues, "Drill Sgt. Norton taught me how to be a soldier: Accountability, humility and putting the unit before yourself. That training stuck."

Cotton then playfully asks Sgt. Norton for permission to speak, before giving the customary commercial tag line that he approved this message.

Cotton and Pryor have been hammering away at each other for months during a series of negative attack ads, full of dark music and unflattering photos, according to The Washington Post.

The Americans for Prosperity, a super PAC founded by the conservative Koch brothers, has targeted Pryor on his support of Obamacare while the Senate Majority PAC has questioned Cotton’s connection to insurance companies.

Pryor has slammed Cotton’s record in the House, particularly his vote to raise the eligibility age for Medicare to 70, while the congressman has called the senator "unfaithful to the truth."

The pair are running neck-and-neck in recent polls, according to USA Today, in what is seen as a vital race for the Democrats who are in danger of losing control of the Senate to the GOP.